ant value, -451.25 + 0.52 kcal. per mole, was combined with the values for the heat of formation of amorphous B203, -300.0 i 0.7 kcal. per mole ( 3 ) ,and with the heat of formation of Ti02 (rutile) (5, 9) -225.4 & 0.2 to give -77.4 & 0.9 kcal. per mole for the heat of formation of TiB2MZ +a.W, as shown in the following equations: TiO,
+ 1.011 B 2 0 3 - TiB,,+ +
2.022B + 1.516 O2
Ti + 0
2
Ti + 2.022B
-
2.516 0
2
LITERATURE CITED Brewer, L., Haraldsen, H., J . Electrochem. SOC. 102, 399 (1955). Epel'baum, V.A., Starostina, M.I., Bor. Tr. Konf. p o Khim. Bora i Ego Soedin. 1955,97 (1958). Huber, E.J., Jr., Head, E.L., Holley, C.E., Jr., J . Phys. Chem.68,3040 (1964). Huber, E.J., Jr., Matthews, C.O., Holley, C.E., Jr., J . A m . Chern. SOC.77,6493 (1955). Humphrey, G.L., Ibid., 73, 1587 (1951). Ibid., p. 2261. Lowell, C.E., Williams, W.S., Reu. Sci. Instr. 32, 1120 (1961). Neumann, B., Kroger, C., Haebler, H., 2. anorg. Chem. 196, 65 (1931). Neumann, B., Kroger, C., Kunz, H., 2. anorg u. allgem. Chem. 218, 379 (1934).
+ 451.25 f 0.52 kcal.
1.011 B203- 303.3 i 0.71 kcal. TiO, - 225.4 f 0.2 kcal. TiB2,-
77.4 f 0.9 kcal.
This value is somewhat more negative than those reported earlier. If it is assumed that most of the oxygen was present as BZ03 instead of TiOz, both the original formula of the material and the heat of formation lie well within the stated uncertainties. ACKNOWLEDGMENT
The authors thank Helen Cowan for chemical analysis,
R. Douglass for microscopic examination, and F. Ellinger
RECEIVED for review February 24, 1966. Accepted May 2, 1966. Work performed under the auspices of the U. S. Atomic Energy
for x-ray analysis.
Commission.
Solubility of Cyclopropane in Some lower Alcohols CHARLES E. LOEFFLER' and JOHN J. McKETTA, Jr. Department of Chemical Engineering, University of Texas, Austin, Tex. The solubility of cyclopropane was determined at 1-atm. partial pressure and 0" to 40' C. in methanol, ethanol, 1 -propanol, 2-propanol, and 1 -butanol.
THE solubility of cyclopropane has been determined a t 1-atm. partial pressure and temperatures ranging from 0" to 40° C. in five lower alcohols: methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol. A .literature survey has shown that the solubilities of many of the common nonpolar gases have not been measured in several of the lower alcohols. EXPERIMENTAL Materials. The cyclopropane was obtained from the Matheson Co. and had a reported minimum purity of I
Present address: Celanese Chemical Co., Corpus Christi, Tex.
99.5%, which was confirmed by mass spectrometry. N o
further purification was performed. The alcohols were dried with Linde Type 4A molecular sieves using a Soxhlet extraction unit (6). They were then distilled in a laboratory fractionation column of about 30 theoretical plates packed with %-inch i.d., single-turn helices. Central cuts were collected and used. The sources and physical properties of the alcohols are summarized in Table I. In each case, the alcohols had a purity of greater than 99.7% and a water content of 0.1% or less as indicated by chromatographic analysis. Apparatus and Procedures. The apparatus and method have been described (7).
Table I. Sources and Physical Properties of the Alcohols Refractive Index, 25" C.
Vendor's Specifications B.P., C. 64.6
Exptl. 1.3266
.. . 82.3
1.35946 1.37508
1-Propanol
97.2
1.38323
1-Butanol
117.5
1.39726
Grade Baker analyzed reagent
Alcohol Methanol
Source J. T. Baker Chemical Co.
Ethanol 2-Propanol
U. S. Industrial Chemicals Co. U.S.P. reagent quality J . T. Baker Chemical Co. Baker analyzed reagent
VOL. 1 1 , No. 3, JULY 1966
O
Lit. 1.32663(6) 1.32657(1) 1.35941(2, 6 ) 1.3747 ( 6 ) 1.37527(1 ) 1.38314(6) 1.38355(1) 1.3970 ( 5 ) 1.3974 (5) 1.3973 ( I )
43 1
~~~~
~
Table II. Solubility of Cyclopropane in Alcohols (Partial pressure of cyclopropane = 1 atm.)
P. from Equation 1 Run No.
Alcohol
M-1 M-2 M-3 M-4 M-5 M-6 M-7 M-8 M-9 M-10 M-11 M-12 M-13 M-14 M-15 E-1 E-2 E-3 E-4 E-5 E-6 E-7 E-8 E-9 E-10 E-11 E-12 E-13 E-14 E-15 iP-1 iP-2 iP-3 iP-4 iP-5 iP-6 iP-7 iP-8 iP-9 iP-10 iP-11 iP-12 iP-13 iP-14 nP-1 nP-2 nP-3 nP-4 nP-5 nP-6 nP-7
MeOH
Solubility, Bunsen Coef. T. C . Individual Av. 40 30 20 10 0
EtOH
40 30 20 10
0 iPrOH
40 30 20 10
0 nPrOH
40 30 20
nP-8 nP-9 nP-10 nP-11 B-1 B-2 B-3 B-4 B-5 B-6 B-7 B-8 B-9 B-10
432
0 nBuOH
40 30 20 10 0
10.124 9.548 9.377 13.20 13.28 12.93 16.61 16.87 16.83 22.97 22.94 23.34 32.90 31.92 33.00 10.77 10.96 10.57 14.44 14.26 14.19 19.19 19.07 19.05 26.49 26.43 26.52 38.02 38.26 38.25 11.11 11.05 11.08 14.53 14.67 14.46 19.33 19.27 19.34 26.69 26.57 26.61 39.07 39.48 11.59 11.48 11.33 15.36 15.36 20.61 20.29 28.15 28.15 40.78 40.60 11.88 11.72 15.40 15.34 20.43 20.44 28.33 28.22 40.78 40.78
Po from Raoult’s Law Total
Flubilitv. Bunsen Coef.
Mole fraction
pressure
Individual
0.01796
1036.5
13.14
0.02392
933.0
16.77
0.02998
865.7
23.08
0.04035
822.9
32.61
0.05546
796.6
10.77
0.02839
905.3
8.831 8.625 8.147 12.20 12.08 12.34 16.45 16.58 16.58 22.81 22.74 22.98 32.60 32.12 32.79 10.55
14.30
0.03697
846.6
19.10
0.04831
810.3
26.48
0.06508
788.4
38.18
0.09034
775.7
11.08
0.03793
873.0
14.55
0.04874
825.1
19.31
0.06305
797.0
26.62
0.08407
780.1
38.78
0.1169
770.7
11.47
0.03829
817.5
15.36
0.05012
791.9
20.45
0.06504
776.8
28.15
0.08661
768.4
40.69
0.1195
764.0
11.80
0.04767
780.6
15.37
0.06069
770.8
20.43
0.07845
765.3
28.28
0.1046
762.5
40.78
0.1431
761.1
9.683
10.33 14.26 14.12 14.04 19.00 18.97 18.93 26.35 26.39 26.39 37.89 38.12 38.17 10.92 10.92 10.91 14.42 14.57 14.38 19.21 19.19 19.28 26.59 26.54 26.55 38.11 38.94 11.32 11.32 11.24 15.21 15.26 20.30 20.24 28.10 28.11 40.75 40.55 11.64 11.62 15.30 15.24 20.42 20.40 28.33 28.21 40.81 40.77
Av.
Mole fraction
Total pressure
8.734
0.01623
1012.8
12.21
0.02226
914.6
16.54
0.02958
851.4
22.84
0.03994
811.9
32.50
0.05529
788.1
10.45
0.02757
890.6
14.14
0.03658
835.7
18.97
0.04797
801.9
26.38
0.06484
782.0
38.06
0.09008
770.9
10.92
0.03740
861.0
14.46
0.04843
817.0
19.23
0.06278
790.6
26.56
0.08390
775.5
38.53
0.1162
767.3
11.29
0.03772
810.2
15.24
0.04974
787.0
20.27
0.06451
773.6
28.11
0.08649
766.4
40.65
0.1194
762.8
11.63
0.04701
777.4
15.27
0.06032
768.7
20.41
0.07838
764.1
28.27
0.1046
761.7
40.79
0.1431
760.7
JOURNAL OF CHEMICAL AND ENGINEERING DATA
RESULTS
The solubility data (Table 11) were calculated in units of both mole fraction and Bunsen coefficient (volume of gas a t 1 atm. and 0” per unit volume of solvent when the partial pressure of gas is 1 atm.). Because of low values of gas solubilities, many investigators use the ideal solution laws of Raoult and Henry in their calculations. However, as has been pointed out by Kretschmer and Wiebe ( 3 ) , hydrocarbon-alcohol solutions exhibit large positive deviations from Raoult’s law. I n this investigation, only the total pressure is’measured experimentally. I n order to set the gas partial pressure a t 1atm., the partial pressure of the alcohol was calculated by
methanol, ethanol, and 2-propanol and the equation of Keyes et al (2) was used for 1-propanol and 1-butanol. ACKNOWLEDGMENT
The authors gratefully acknowledge the support given this project by the National Science Foundation. LITERATURE CITED (1) American Petroleum Institute, “Selected Values of Properties of Hydrocarbons and Related Compounds,” API Research Project 44, Camegie Institute of Technology, Pittsburgh. (2) Keyes, FIG., Smith, L.B., Gerry, H.T., Proc. A m . Acad. Arts Sci. 70, 319 (1936). (3) Kretschmer, C.B., Wiebe, R., J. Am. Chem. Soc. 73, 3778
(1951).
where Pais the partial pressure of the alcohol, Po0 its vapor pressure, V, its liquid molal volume, and B, its second virial coefficient. xo and xo are the mole fraction of alcohol and gas, respectively, in solution. PT is the total pressure. A is a constant which is taken equal to 1.6 ( 3 ) . Second virial coefficients were taken from Kretschmer and Wiebe ( 4 ) for
VOL. 1 1 , No. 3, JULY 1966
(4) Ibid., 76, 2579 (1954). (5) Timmermans, J., “Physico-Chemical Constants of
Pure Organic Compounds,” Elsevier, New York, 1950. (6) Weissberger, A., “Organic Solvents,” Interscience, New York, 1955. (7) Yen, L.C., McKetta, J.J., J. CHEM.ENG.DATA7, 288 (1962). RECEIVED for review February 28, 1966. Accepted April 9, 1966.
433
